11/19/2016 8:45 PM
Contingency anchors... pretty good idea for certain applications. Very common in canyoneering but also used in other disciplines, sometimes referred to as Rig for Lower. Too often we get to the edge of whatever vertical drop we are working at, clip in to the anchor...and toss our rope bag over and get on with the business at hand. If we find ourselves in one of the following instances... a contingency anchor / rappel station might be prudent...
- Guiding a group of people...with marginal experience
- Working in an area with variable environmental pathology...like a high potential for injury
- Potential for someone getting something hung up in their DCD
- 2-stage rescues...when you may need to rappel down a distance and lock off - pick-off a casualty, then have the team above lower you and casualty down remainder of vertical space
Downside...rule of thumb, you need your rope to be about twice the distance of the drop...obviously it depends on where the person descending gets in trouble...but off this same system you can raise too (next video), so there is some wiggle room for cheating based on environment.
In this video we are using the Rescue Craft Access / Evacuation Kit ( https://www.tacmedsolutions.com/product/rescue-crafttm-evacuation-rope-kit/ ). We are using the Totem Descent Device, and rigging it in throttle mode. Why we dig throttle mode...? It allows us to easily lever the Totem to increase or decrease friction depending on the load weight and environmental structures. So in a nutshell...feed out enough rope to reach the ground, keep the remainder in the rope bag. Rig your contingency and lock it off with a technique you can release under tension. If you don't have any special kit, you can do this a million ways, including a Munter...then tie off with a Mule or Monster Munter Tie Off. If a problem occurs with someone on a rappel, you can then remove your tie off and lower them to the ground (or after next two video...raise them).
In the vertical world, crap happens. Keep yourself and team ready to manage the outlier event. Depending on your environment, even if you don't feel like carrying a long piece of rope, have a back-up rope with another team member, join the ropes and pass a knot if a problem arises, or rig it so the knot is on the load side of your descent device making your transition to a lower quick and efficient.
Element Rescue, Knot Series (11/19/2016)